Repository files navigation

Thepg_pathman module provides optimized partitioning mechanism and functions to manage partitions.

The extension is compatible with PostgreSQL 9.5+.

Partitioning means splitting one large table into smaller pieces. Each row in such table is moved to a single partition according to the partitioning key. PostgreSQL supports partitioning via table inheritance: each partition must be created as a child table with CHECK CONSTRAINT. For example:

CREATE TABLE test (id SERIAL PRIMARY KEY, title TEXT);CREATE TABLE test_1 (CHECK ( id >= 100 AND id < 200 )) INHERITS (test);CREATE TABLE test_2 (CHECK ( id >= 200 AND id < 300 )) INHERITS (test);

Despite the flexibility, this approach forces the planner to perform an exhaustive search and to check constraints on each partition to determine whether it should be present in the plan or not. Large amount of partitions may result in significant planning overhead.

Thepg_pathman module features partition managing functions and optimized planning mechanism which utilizes knowledge of the partitions' structure. It stores partitioning configuration in thepathman_config table; each row contains a single entry for a partitioned table (relation name, partitioning column and its type). During the initialization stage thepg_pathman module caches some information about child partitions in the shared memory, which is used later for plan construction. Before a SELECT query is executed,pg_pathman traverses the condition tree in search of expressions like:

VARIABLE OP CONST

whereVARIABLE is a partitioning key,OP is a comparison operator (supported operators are =, <, <=, >, >=),CONST is a scalar value. For example:

WHERE id = 150

Based on the partitioning type and condition's operator,pg_pathman searches for the corresponding partitions and builds the plan. Currentlypg_pathman supports two partitioning schemes:

• RANGE - maps rows to partitions using partitioning key ranges assigned to each partition. Optimization is achieved by using the binary search algorithm;
• HASH - maps rows to partitions using a generic hash function.

More interesting features are yet to come. Stay tuned!

• HASH and RANGE partitioning schemes;
• Both automatic and manual partition management;
• Support for integer, floating point, date and other types, including domains;
• Effective query planning for partitioned tables (JOINs, subselects etc);
• RuntimeAppend &RuntimeMergeAppend custom plan nodes to pick partitions at runtime;
• PartitionFilter: an efficient drop-in replacement for INSERT triggers;
• Automatic partition creation for new INSERTed data (only for RANGE partitioning);
• ImprovedCOPY FROM\TO statement that is able to insert rows directly into partitions;
• UPDATE triggers generation out of the box (will be replaced with custom nodes too);
• User-defined callbacks for partition creation event handling;
• Non-blocking concurrent table partitioning;
• FDW support (foreign partitions);
• Various GUC toggles and configurable settings.

• Implement LIST partitioning scheme;
• Optimize hash join (both tables are partitioned by join key).

To installpg_pathman, execute this in the module's directory:

make install USE_PGXS=1

Modify theshared_preload_libraries parameter inpostgresql.conf as following:

shared_preload_libraries = 'pg_pathman'

Important:pg_pathman may cause conflicts with some other extensions that use the same hook functions. For example,pg_pathman usesProcessUtility_hook to handle COPY queries for partitioned tables, which means it may interfere withpg_stat_statements from time to time. In this case, try listing libraries in certain order:shared_preload_libraries = 'pg_stat_statements, pg_pathman'.

It is essential to restart the PostgreSQL instance. After that, execute the following query in psql:

CREATE EXTENSION pg_pathman;

Done! Now it's time to setup your partitioning schemes.

Important: Don't forget to set thePG_CONFIG variable in case you want to testpg_pathman on a custom build of PostgreSQL. Read morehere.

In order to update pg_pathman:

1. Install the lateststable release of pg_pathman.
2. Restart your PostgreSQL cluster.
3. Execute the following queries:

/* replace X.Y with the version number, e.g. 1.3 */ALTER EXTENSION pg_pathman UPDATE TO "X.Y";SET pg_pathman.enable = t;

create_hash_partitions(relation         REGCLASS,                       attribute        TEXT,                       partitions_count INTEGER,                       partition_data   BOOLEAN DEFAULT TRUE,                       partition_names  TEXT[] DEFAULT NULL,                       tablespaces      TEXT[] DEFAULT NULL)

Performs HASH partitioning forrelation by integer keyattribute. Thepartitions_count parameter specifies the number of partitions to create; it cannot be changed afterwards. Ifpartition_data istrue then all the data will be automatically copied from the parent table to partitions. Note that data migration may took a while to finish and the table will be locked until transaction commits. Seepartition_table_concurrently() for a lock-free way to migrate data. Partition creation callback is invoked for each partition if set beforehand (seeset_init_callback()).

create_range_partitions(relation       REGCLASS,                        attribute      TEXT,                        start_value    ANYELEMENT,                        p_interval     ANYELEMENT,                        p_count        INTEGER DEFAULT NULL                        partition_data BOOLEAN DEFAULT TRUE)create_range_partitions(relation       REGCLASS,                        attribute      TEXT,                        start_value    ANYELEMENT,                        p_interval     INTERVAL,                        p_count        INTEGER DEFAULT NULL,                        partition_data BOOLEAN DEFAULT TRUE)

Performs RANGE partitioning forrelation by partitioning keyattribute,start_value argument specifies initial value,p_interval sets the default range for auto created partitions or partitions created withappend_range_partition() orprepend_range_partition() (ifNULL then auto partition creation feature won't work),p_count is the number of premade partitions (if not set thenpg_pathman tries to determine it based on attribute values). Partition creation callback is invoked for each partition if set beforehand.

create_partitions_from_range(relation       REGCLASS,                             attribute      TEXT,                             start_value    ANYELEMENT,                             end_value      ANYELEMENT,                             p_interval     ANYELEMENT,                             partition_data BOOLEAN DEFAULT TRUE)create_partitions_from_range(relation       REGCLASS,                             attribute      TEXT,                             start_value    ANYELEMENT,                             end_value      ANYELEMENT,                             p_interval     INTERVAL,                             partition_data BOOLEAN DEFAULT TRUE)

Performs RANGE-partitioning from specified range forrelation by partitioning keyattribute. Partition creation callback is invoked for each partition if set beforehand.

partition_table_concurrently(relation   REGCLASS,                             batch_size INTEGER DEFAULT 1000,                             sleep_time FLOAT8 DEFAULT 1.0)

Starts a background worker to move data from parent table to partitions. The worker utilizes short transactions to copy small batches of data (up to 10K rows per transaction) and thus doesn't significantly interfere with user's activity. If the worker is unable to lock rows of a batch, it sleeps forsleep_time seconds before the next attempt and tries again up to 60 times, and quits if it's still unable to lock the batch.

stop_concurrent_part_task(relation REGCLASS)

Stops a background worker performing a concurrent partitioning task. Note: worker will exit after it finishes relocating a current batch.

create_hash_update_trigger(parent REGCLASS)

Creates the trigger on UPDATE for HASH partitions. The UPDATE trigger isn't created by default because of the overhead. It's useful in cases when the key attribute might change.

create_range_update_trigger(parent REGCLASS)

Same as above, but for a RANGE-partitioned table.

replace_hash_partition(old_partition REGCLASS,                       new_partition REGCLASS,                       lock_parent   BOOL DEFAULT TRUE)

Replaces specified partition of HASH-partitioned table with another table. Thelock_parent parameter will prevent any INSERT/UPDATE/ALTER TABLE queries to parent table.

split_range_partition(partition      REGCLASS,                      split_value    ANYELEMENT,                      partition_name TEXT DEFAULT NULL)

Split RANGEpartition in two bysplit_value. Partition creation callback is invoked for a new partition if available.

merge_range_partitions(partition1 REGCLASS, partition2 REGCLASS)

Merge two adjacent RANGE partitions. First, data frompartition2 is copied topartition1, thenpartition2 is removed.

merge_range_partitions(partitions REGCLASS[])

Merge several adjacent RANGE partitions (partitions must be specified in ascending or descending order). All the data will be accumulated in the first partition.

append_range_partition(parent         REGCLASS,                       partition_name TEXT DEFAULT NULL,                       tablespace     TEXT DEFAULT NULL)

Append new RANGE partition withpathman_config.range_interval as interval.

prepend_range_partition(parent         REGCLASS,                        partition_name TEXT DEFAULT NULL,                        tablespace     TEXT DEFAULT NULL)

Prepend new RANGE partition withpathman_config.range_interval as interval.

add_range_partition(relation       REGCLASS,                    start_value    ANYELEMENT,                    end_value      ANYELEMENT,                    partition_name TEXT DEFAULT NULL,                    tablespace     TEXT DEFAULT NULL)

Create new RANGE partition forrelation with specified range bounds. Ifstart_value orend_value are NULL then corresponding range bound will be infinite.

drop_range_partition(partition TEXT, delete_data BOOLEAN DEFAULT TRUE)

Drop RANGE partition and all of its data ifdelete_data is true.

attach_range_partition(relation    REGCLASS,                       partition   REGCLASS,                       start_value ANYELEMENT,                       end_value   ANYELEMENT)

Attach partition to the existing RANGE-partitioned relation. The attached table must have exactly the same structure as the parent table, including the dropped columns. Partition creation callback is invoked if set (seepathman_config_params).

detach_range_partition(partition REGCLASS)

Detach partition from the existing RANGE-partitioned relation.

disable_pathman_for(relation TEXT)

Permanently disablepg_pathman partitioning mechanism for the specified parent table and remove the insert trigger if it exists. All partitions and data remain unchanged.

drop_partitions(parent      REGCLASS,                delete_data BOOLEAN DEFAULT FALSE)

Drop partitions of theparent table (both foreign and local relations). Ifdelete_data isfalse, the data is copied to the parent table first. Default isfalse.

set_interval(relation REGCLASS, value ANYELEMENT)

Update RANGE partitioned table interval. Note that interval must not be negative and it must not be trivial, i.e. its value should be greater than zero for numeric types, at least 1 microsecond forTIMESTAMP and at least 1 day forDATE.

set_enable_parent(relation REGCLASS, value BOOLEAN)

Include/exclude parent table into/from query plan. In original PostgreSQL planner parent table is always included into query plan even if it's empty which can lead to additional overhead. You can usedisable_parent() if you are never going to use parent table as a storage. Default value depends on thepartition_data parameter that was specified during initial partitioning increate_range_partitions() orcreate_partitions_from_range() functions. If thepartition_data parameter wastrue then all data have already been migrated to partitions and parent table disabled. Otherwise it is enabled.

set_auto(relation REGCLASS, value BOOLEAN)

Enable/disable auto partition propagation (only for RANGE partitioning). It is enabled by default.

set_init_callback(relation REGCLASS, callback REGPROC DEFAULT 0)

Set partition creation callback to be invoked for each attached or created partition (both HASH and RANGE). The callback must have the following signature:part_init_callback(args JSONB) RETURNS VOID. Parameterarg consists of several fields whose presence depends on partitioning type:

/* RANGE-partitioned table abc (child abc_4) */{    "parent":           "abc",    "parent_schema":    "public",    "parttype":         "2",    "partition":        "abc_4",    "partition_schema": "public",    "range_max":        "401",    "range_min":        "301"}/* HASH-partitioned table abc (child abc_0) */{    "parent":           "abc",    "parent_schema":    "public",    "parttype":         "1",    "partition":        "abc_0",    "partition_schema": "public"}

set_set_spawn_using_bgw(relation REGCLASS, value BOOLEAN)

When INSERTing new data beyond the partitioning range, use SpawnPartitionsWorker to create new partitions in a separate transaction.

CREATE TABLE IF NOT EXISTS pathman_config (    partrel         REGCLASS NOT NULL PRIMARY KEY,    attname         TEXT NOT NULL,    parttype        INTEGER NOT NULL,    range_interval  TEXT);

This table stores a list of partitioned tables.

CREATE TABLE IF NOT EXISTS pathman_config_params (    partrel         REGCLASS NOT NULL PRIMARY KEY,    enable_parent   BOOLEAN NOT NULL DEFAULT TRUE,    auto            BOOLEAN NOT NULL DEFAULT TRUE,    init_callback   REGPROCEDURE NOT NULL DEFAULT 0,    spawn_using_bgw BOOLEAN NOT NULL DEFAULT FALSE);

This table stores optional parameters which override standard behavior.

-- helper SRF functionCREATE OR REPLACE FUNCTION show_concurrent_part_tasks()RETURNS TABLE (    userid     REGROLE,    pid        INT,    dbid       OID,    relid      REGCLASS,    processed  INT,    status     TEXT)AS 'pg_pathman', 'show_concurrent_part_tasks_internal'LANGUAGE C STRICT;CREATE OR REPLACE VIEW pathman_concurrent_part_tasksAS SELECT * FROM show_concurrent_part_tasks();

This view lists all currently running concurrent partitioning tasks.

-- helper SRF functionCREATE OR REPLACE FUNCTION show_partition_list()RETURNS TABLE (    parent     REGCLASS,    partition  REGCLASS,    parttype   INT4,    partattr   TEXT,    range_min  TEXT,    range_max  TEXT)AS 'pg_pathman', 'show_partition_list_internal'LANGUAGE C STRICT;CREATE OR REPLACE VIEW pathman_partition_listAS SELECT * FROM show_partition_list();

This view lists all existing partitions, as well as their parents and range boundaries (NULL for HASH partitions).

pg_pathman provides a couple ofcustom plan nodes which aim to reduce execution time, namely:

• RuntimeAppend (overridesAppend plan node)
• RuntimeMergeAppend (overridesMergeAppend plan node)
• PartitionFilter (drop-in replacement for INSERT triggers)

PartitionFilter acts as aproxy node for INSERT's child scan, which means it can redirect output tuples to the corresponding partition:

EXPLAIN (COSTS OFF)INSERT INTO partitioned_tableSELECT generate_series(1, 10), random();               QUERY PLAN----------------------------------------- Insert on partitioned_table   ->  Custom Scan (PartitionFilter)         ->  Subquery Scan on "*SELECT*"               ->  Result(4 rows)

RuntimeAppend andRuntimeMergeAppend have much in common: they come in handy in a case when WHERE condition takes form of:

VARIABLE OP PARAM

This kind of expressions can no longer be optimized at planning time since the parameter's value is not known until the execution stage takes place. The problem can be solved by embedding theWHERE condition analysis routine into the originalAppend's code, thus making it pick only required scans out of a whole bunch of planned partition scans. This effectively boils down to creation of a custom node capable of performing such a check.

There are at least several cases that demonstrate usefulness of these nodes:

/* create table we're going to partition */CREATE TABLE partitioned_table(id INT NOT NULL, payload REAL);/* insert some data */INSERT INTO partitioned_tableSELECT generate_series(1, 1000), random();/* perform partitioning */SELECT create_hash_partitions('partitioned_table', 'id', 100);/* create ordinary table */CREATE TABLE some_table AS SELECT generate_series(1, 100) AS VAL;

• id = (select ... limit 1)

EXPLAIN (COSTS OFF, ANALYZE) SELECT * FROM partitioned_tableWHERE id = (SELECT * FROM some_table LIMIT 1);                                             QUERY PLAN---------------------------------------------------------------------------------------------------- Custom Scan (RuntimeAppend) (actual time=0.030..0.033 rows=1 loops=1)   InitPlan 1 (returns $0)     ->  Limit (actual time=0.011..0.011 rows=1 loops=1)           ->  Seq Scan on some_table (actual time=0.010..0.010 rows=1 loops=1)   ->  Seq Scan on partitioned_table_70 partitioned_table (actual time=0.004..0.006 rows=1 loops=1)         Filter: (id = $0)         Rows Removed by Filter: 9 Planning time: 1.131 ms Execution time: 0.075 ms(9 rows)/* disable RuntimeAppend node */SET pg_pathman.enable_runtimeappend = f;EXPLAIN (COSTS OFF, ANALYZE) SELECT * FROM partitioned_tableWHERE id = (SELECT * FROM some_table LIMIT 1);                                    QUERY PLAN---------------------------------------------------------------------------------- Append (actual time=0.196..0.274 rows=1 loops=1)   InitPlan 1 (returns $0)     ->  Limit (actual time=0.005..0.005 rows=1 loops=1)           ->  Seq Scan on some_table (actual time=0.003..0.003 rows=1 loops=1)   ->  Seq Scan on partitioned_table_0 (actual time=0.014..0.014 rows=0 loops=1)         Filter: (id = $0)         Rows Removed by Filter: 6   ->  Seq Scan on partitioned_table_1 (actual time=0.003..0.003 rows=0 loops=1)         Filter: (id = $0)         Rows Removed by Filter: 5         ... /* more plans follow */ Planning time: 1.140 ms Execution time: 0.855 ms(306 rows)

• id = ANY (select ...)

EXPLAIN (COSTS OFF, ANALYZE) SELECT * FROM partitioned_tableWHERE id = any (SELECT * FROM some_table limit 4);                                                QUERY PLAN----------------------------------------------------------------------------------------------------------- Nested Loop (actual time=0.025..0.060 rows=4 loops=1)   ->  Limit (actual time=0.009..0.011 rows=4 loops=1)         ->  Seq Scan on some_table (actual time=0.008..0.010 rows=4 loops=1)   ->  Custom Scan (RuntimeAppend) (actual time=0.002..0.004 rows=1 loops=4)         ->  Seq Scan on partitioned_table_70 partitioned_table (actual time=0.001..0.001 rows=10 loops=1)         ->  Seq Scan on partitioned_table_26 partitioned_table (actual time=0.002..0.003 rows=9 loops=1)         ->  Seq Scan on partitioned_table_27 partitioned_table (actual time=0.001..0.002 rows=20 loops=1)         ->  Seq Scan on partitioned_table_63 partitioned_table (actual time=0.001..0.002 rows=9 loops=1) Planning time: 0.771 ms Execution time: 0.101 ms(10 rows)/* disable RuntimeAppend node */SET pg_pathman.enable_runtimeappend = f;EXPLAIN (COSTS OFF, ANALYZE) SELECT * FROM partitioned_tableWHERE id = any (SELECT * FROM some_table limit 4);                                       QUERY PLAN----------------------------------------------------------------------------------------- Nested Loop Semi Join (actual time=0.531..1.526 rows=4 loops=1)   Join Filter: (partitioned_table.id = some_table.val)   Rows Removed by Join Filter: 3990   ->  Append (actual time=0.190..0.470 rows=1000 loops=1)         ->  Seq Scan on partitioned_table (actual time=0.187..0.187 rows=0 loops=1)         ->  Seq Scan on partitioned_table_0 (actual time=0.002..0.004 rows=6 loops=1)         ->  Seq Scan on partitioned_table_1 (actual time=0.001..0.001 rows=5 loops=1)         ->  Seq Scan on partitioned_table_2 (actual time=0.002..0.004 rows=14 loops=1)... /* 96 scans follow */   ->  Materialize (actual time=0.000..0.000 rows=4 loops=1000)         ->  Limit (actual time=0.005..0.006 rows=4 loops=1)               ->  Seq Scan on some_table (actual time=0.003..0.004 rows=4 loops=1) Planning time: 2.169 ms Execution time: 2.059 ms(110 rows)

• NestLoop involving a partitioned table, which is omitted since it's occasionally shown above.

In case you're interested, you can read more about custom nodes at Alexander Korotkov'sblog.

• You can easily addpartition column containing the names of the underlying partitions using the system attribute calledtableoid:

SELECT tableoid::regclass AS partition, * FROM partitioned_table;

• Though indices on a parent table aren't particularly useful (since it's supposed to be empty), they act as prototypes for indices on partitions. For each index on the parent table,pg_pathman will create a similar index on every partition.

• All running concurrent partitioning tasks can be listed using thepathman_concurrent_part_tasks view:

SELECT * FROM pathman_concurrent_part_tasks; userid | pid  | dbid  | relid | processed | status  --------+------+-------+-------+-----------+--------- dmitry | 7367 | 16384 | test  |    472000 | working(1 row)

• pathman_partition_list in conjunction withdrop_range_partition() can be used to drop RANGE partitions in a more flexible way compared to good oldDROP TABLE:

SELECT drop_range_partition(partition, false) /* move data to parent */FROM pathman_partition_listWHERE parent = 'part_test'::regclass AND range_min::int < 500;NOTICE:  1 rows copied from part_test_11NOTICE:  100 rows copied from part_test_1NOTICE:  100 rows copied from part_test_2 drop_range_partition ---------------------- dummy_test_11 dummy_test_1 dummy_test_2(3 rows)

• You can turn foreign tables into partitions using theattach_range_partition() function. Rows that were meant to be inserted into parent will be redirected to foreign partitions (as usual, PartitionFilter will be involved), though by default it is prohibited to insert rows into partitions provided not bypostgres_fdw. Only superuser is allowed to setpg_pathman.insert_into_fdw GUC variable.

Consider an example of HASH partitioning. First create a table with some integer column:

CREATE TABLE items (    id       SERIAL PRIMARY KEY,    name     TEXT,    code     BIGINT);INSERT INTO items (id, name, code)SELECT g, md5(g::text), random() * 100000FROM generate_series(1, 100000) as g;

Now run thecreate_hash_partitions() function with appropriate arguments:

SELECT create_hash_partitions('items', 'id', 100);

This will create new partitions and move the data from parent to partitions.

Here's an example of the query performing filtering by partitioning key:

SELECT * FROM items WHERE id = 1234;  id  |               name               | code------+----------------------------------+------ 1234 | 81dc9bdb52d04dc20036dbd8313ed055 | 1855(1 row)EXPLAIN SELECT * FROM items WHERE id = 1234;                                     QUERY PLAN------------------------------------------------------------------------------------ Append  (cost=0.28..8.29 rows=0 width=0)   ->  Index Scan using items_34_pkey on items_34  (cost=0.28..8.29 rows=0 width=0)         Index Cond: (id = 1234)

Notice that theAppend node contains only one child scan which corresponds to the WHERE clause.

Important: pay attention to the fact thatpg_pathman excludes the parent table from the query plan.

To access parent table use ONLY modifier:

EXPLAIN SELECT * FROM ONLY items;                      QUERY PLAN------------------------------------------------------ Seq Scan on items  (cost=0.00..0.00 rows=1 width=45)

Consider an example of RANGE partitioning. Let's create a table containing some dummy logs:

CREATE TABLE journal (    id      SERIAL,    dt      TIMESTAMP NOT NULL,    level   INTEGER,    msg     TEXT);-- similar index will also be created for each partitionCREATE INDEX ON journal(dt);-- generate some dataINSERT INTO journal (dt, level, msg)SELECT g, random() * 6, md5(g::text)FROM generate_series('2015-01-01'::date, '2015-12-31'::date, '1 minute') as g;

Run thecreate_range_partitions() function to create partitions so that each partition would contain the data for one day:

SELECT create_range_partitions('journal', 'dt', '2015-01-01'::date, '1 day'::interval);

It will create 365 partitions and move the data from parent to partitions.

New partitions are appended automaticaly by insert trigger, but it can be done manually with the following functions:

-- add new partition with specified rangeSELECT add_range_partition('journal', '2016-01-01'::date, '2016-01-07'::date);-- append new partition with default rangeSELECT append_range_partition('journal');

The first one creates a partition with specified range. The second one creates a partition with default interval and appends it to the partition list. It is also possible to attach an existing table as partition. For example, we may want to attach an archive table (or even foreign table from another server) for some outdated data:

CREATE FOREIGN TABLE journal_archive (    id      INTEGER NOT NULL,    dt      TIMESTAMP NOT NULL,    level   INTEGER,    msg     TEXT)SERVER archive_server;SELECT attach_range_partition('journal', 'journal_archive', '2014-01-01'::date, '2015-01-01'::date);

Important: the definition of the attached table must match the one of the existing partitioned table, including the dropped columns.

To merge to adjacent partitions, use themerge_range_partitions() function:

SELECT merge_range_partitions('journal_archive', 'journal_1');

To split partition by value, use thesplit_range_partition() function:

SELECT split_range_partition('journal_366', '2016-01-03'::date);

To detach partition, use thedetach_range_partition() function:

SELECT detach_range_partition('journal_archive');

Here's an example of the query performing filtering by partitioning key:

SELECT * FROM journal WHERE dt >= '2015-06-01' AND dt < '2015-06-03';   id   |         dt          | level |               msg--------+---------------------+-------+---------------------------------- 217441 | 2015-06-01 00:00:00 |     2 | 15053892d993ce19f580a128f87e3dbf 217442 | 2015-06-01 00:01:00 |     1 | 3a7c46f18a952d62ce5418ac2056010c 217443 | 2015-06-01 00:02:00 |     0 | 92c8de8f82faf0b139a3d99f2792311d ...(2880 rows)EXPLAIN SELECT * FROM journal WHERE dt >= '2015-06-01' AND dt < '2015-06-03';                            QUERY PLAN------------------------------------------------------------------ Append  (cost=0.00..58.80 rows=0 width=0)   ->  Seq Scan on journal_152  (cost=0.00..29.40 rows=0 width=0)   ->  Seq Scan on journal_153  (cost=0.00..29.40 rows=0 width=0)(3 rows)

There are several user-accessibleGUC variables designed to toggle the whole module or specific custom nodes on and off:

• pg_pathman.enable --- disable (or enable)pg_pathmancompletely
• pg_pathman.enable_runtimeappend --- toggleRuntimeAppend custom node on\off
• pg_pathman.enable_runtimemergeappend --- toggleRuntimeMergeAppend custom node on\off
• pg_pathman.enable_partitionfilter --- togglePartitionFilter custom node on\off
• pg_pathman.enable_auto_partition --- toggle automatic partition creation on\off (per session)
• pg_pathman.enable_bounds_cache --- toggle bounds cache on\off (faster updates of partitioning scheme)
• pg_pathman.insert_into_fdw --- allow INSERTs into various FDWs(disabled | postgres | any_fdw)
• pg_pathman.override_copy --- toggle COPY statement hooking on\off

Topermanently disablepg_pathman for some previously partitioned table, use thedisable_pathman_for() function:

SELECT disable_pathman_for('range_rel');

All sections and data will remain unchanged and will be handled by the standard PostgreSQL inheritance mechanism.

Do not hesitate to post your issues, questions and new ideas at theissues page.

Ildar Musin <i.musin(at)postgrespro.ru> Postgres Professional Ltd., Russia
Alexander Korotkov <a.korotkov(at)postgrespro.ru> Postgres Professional Ltd., Russia
Dmitry Ivanov <d.ivanov(at)postgrespro.ru> Postgres Professional Ltd., Russia
Maksim Milyutin <m.milyutin(at)postgrespro.ru> Postgres Professional Ltd., Russia